Granitic Rock Samples Research Articles

Evolution of rare earth elements, uranium and thorium in geological samples by ICP-OES and their characterization

Inductively coupled plasma optical emission spectrometry (ICP-OES) was used to determine rare earth elements, uranium and thorium in granitic soils and rock samples collected from Chumporn and Surat Thani provinces, the southern part of Thailand. The effect of digestion temperature (125 °C, 160 °C, 200 °C and 240 °C) on the concentration levels of elements was investigated. It was found that the digestion temperature of 160 °C had an efficient to leach out the elements to achieve the high concentration of elements for soil samples at different horizons such as O-A, A-B, B-C (1) and B-C(2). For rock sample (D horizon), the digestion temperature did not significantly affect to extract the elements. The results of the analytical study were also compared with the results determined by ICP-MS/OES as obtained from Department of Mineral Resources, Thailand (DMR). A good correlation between the determined values digested at 160 °C and the values measured by ICP-MS/OES as obtained from DMR were found for Ce, La, Pr, Nd, Y, Dy, Eu and Th. The SEM-EDS results demonstrated that the samples particles mainly consisted of Si, and Al with varying amount of Fe, K, Mg, Ca, Na and Ti. Quartz and albite were found to exist in all samples that were confirmed by XRD analysis.

Assessment of shielding potentials and radiological safety indices of Nigerian granite rocks

The activity concentration of primordial radioisotopes (238U,232Th and 40K) in granite rock samples from Minna, North central Nigeria were measured using a sensitive HPGe detector for gamma spectrometric measurement. Five granite rock samples were collected from Maikunkele, Bosso, Maitumbi, Chanchaga and Paiko areas of the town. The average activity concentrations for the radionuclides in the rocks were: 27 ± 4 Bq/kg; 48 ± 7 Bq/kg and 874 ± 86 Bq/kg for 238U, 232Th and 40K respectively. The average absorbed dose rate, effective dose; radium equivalent (Req) and internal hazard index (Hin) were 65 ± 10 nG/h; 0.32 ± 0.05 mSv/y; 140 ± 21 Bq/kg and 0.45 ± 0.07 respectively. All the rock samples had Req less than the recommended safety value of 370 Bq/kg. All evaluated radiological safety indices fell within the recommended safety limits and world average values. The analysis of radionuclide content of the granite rocks showed that they do not pose environmental radiation risk to humans when used as structural shielding materials. Mass attenuation coefficients of the granite samples evaluated via the WinXcom computer code suggested that the granite rocks considered have good shielding capacity comparable to that of ordinary concrete.Keywords: Radionuclide; radiation effect; shielding; dose assessment; granite

The Effect of Mineralogical Composition on Strength and Drillability of Granitic Rocks in Hulu Langat, Selangor Malaysia

The strength characteristics of a rock is a criterion for its ability to be drilled and fractured. The uniaxial compressive strength (UCS) is the most commonly used strength index in construction industry and in rock engineering projects. Therefore, a comprehensive knowledge on the factors that could influence the value of the compressive strength is essential in any rock engineering project. This paper explores the effects of mineralogical composition on the UCS value of granitic rocks to evaluate its drillability. Samples of granitic rocks were collected from the Interstate Raw Water Transfer Tunnel project. The rock samples were characterized with quantitative Rietveld XRD method to quantify the relative mineral phase compositions in the rock samples. The relationships between mineralogical properties and UCS were investigated by simple regression analysis. The strength of the rock samples increases with higher composition of quartz and decreases with increase in the composition of feldspar and kaolinite. The positive effects of quartz on the strength of the granitic rock is more significant than the negative influence of feldspar and clay content. The drilling rate varies inversely with the UCS.

Petrogenesis of Volcanic Arc Granites from Bayah Complex, Banten, Indonesia

This research aimed to reveal the petrogenesis of granitic rocks of Bayah Complex starting from magma differentiation to exposing event, this research also intended to determine the tectonic environment. The methods carried out in this research include field observation, petrographic analysis using polarized light microscopy, and geochemical analysis using X-Ray Fluorescence (XRF) and Inductively Coupled Mass Spectrometry (ICP-MS).
 Petrographic analysis shows that Bayah granitic rocks are composed of quartz, plagioclase, and K-feldspar while the rest are amphibole, biotite, sericite, chlorite, epidote, and opaque. Based on its major oxide concentrations, Bayah granitic rocks classified as granite and diorite-quartz which have high-K calc-alkaline magma. 4 samples of granitic rocks showed the A/N+K+C > 1 molar ratios belonging to the peraluminous S-type granite index while the remaining 1 sample showed a molar ratio of A/N+ K+C < 1 and A/N+K > 1 which classified as metaluminous I-type granite. Accordingly, Bayah granitic rocks are S-type granite which crystallized from sediment-derived magma, the sediments itself estimated sourced from continental especially Malay Peninsula, Indonesian Tin Island, and Schwaner Mountains. During differentiation, the magma undergone crustal contamination reflected by the increase in both SiO2 0.51 wt% and Al2O3 1.95 wt%, and decrease in Fe2O3 + MgO 0.61 wt% from the pure composition of sediment-derived magma. Furthermore, the occurrence of crustal contamination also recognized from high concentrations of Rb and Ba which indicate the interaction of magma with the materials of continental crust.
 Regard to the exposing event, Bayah granitic rocks approximated to be exposed due to regional tectonic activity which caused Orogenesa I in the Early Oligocene to the Late Oligocene. Moreover, based on the plot of trace elements especially Rb, Y, Nb, Ta, and Yb on Harker and tectonic discriminant diagrams, Bayah granitic rocks are formed on volcanic-arc active continental margins in accordance with regional tectonic setting.

Micro-scale granite permeability estimation based on digital image analysis

Permeability is a key parameter in describing the flow conductivity of rocks. But experimental measurements of the parameter not only consume time but also only provide us with limited data number. By analyzing digital images of cast thin sections of rock samples in micro-scale, this study presented a systematic method of extracting geometric parameters of fractures and applied it to the granite rock samples from fault F4 in Gansu Beishan, China, which have low permeability and poor water-containing property. With the extracted geometric parameters, the rock permeabilities were estimated by Kozeny-Carman equation and Lattice Boltzmann simulation and were compared with those obtained by pulse decay technique. The results show that although there exists abnormal values in the estimated porosities and permeabilities, in general the relative error is only about onefold for the conditions used in this study. The method proposed here would be useful in the permeability and porosity estimation for fractured rocks that have low hydraulic conductivity.

Complex analysis of uniaxial compressive tests of the Mórágy granitic rock formation (Hungary)

Abstract Understanding the quality of intact rock is one of the most important parts of any engineering projects in the field of rock mechanics. The expression of correlations between the engineering properties of intact rock has always been the scope of experimental research, driven by the need to depict the actual behaviour of rock and to calculate most accurately the design parameters. To determine the behaviour of intact rock, the value of important mechanical parameters such as Young’s modulus (E), Poisson’s ratio (ν) and the strength of rock (σcd) was calculated. Recently, for modelling the behaviour of intact rock, the crack initiation stress (σci) is another important parameter, together with the strain (σ). The ratio of Young’s modulus and the strength of rock is the modulus ratio (M R), which can be used for calculations. These parameters are extensively used in rock engineering when the deformation of different structural elements of underground storage, caverns, tunnels or mining opening must be computed. The objective of this paper is to investigate the relationship between these parameters for Hungarian granitic rock samples. To achieve this goal, the modulus ratio (M R = E/σc) of 50 granitic rocks collected from Bátaapáti radioactive waste repository was examined. Fifty high-precision uniaxial compressive tests were conducted on strong (σc >100 MPa) rock samples, exhibiting the wide range of elastic modulus (E = 57.425–88.937 GPa), uniaxial compressive strength (σc = 133.34–213.04 MPa) and Poisson’s ratio (ν = 0.18–0.32). The observed value (M R = 326–597) and mean value of M R = 439.4 are compared with the results of similar previous researches. Moreover, the statistical analysis for all studied rocks was performed and the relationshipbetween M R and other mechanical parameters such as maximum axial strain ( ε a, max ) $\left( {{\varepsilon }_{\text{a,}\,\text{max}}} \right)$ for studied rocks was discussed.

Combined Microspectroscopic Characterization of a Red-Colored Granite Rock Sample.

Combined microspectroscopic mapping have been conducted on a red-colored Tenzan granite sample by using an original visible-fluorescence-Raman microspectrometer together with a low vacuum scanning electron microscopy-energy dispersive spectrometry (SEM-EDS) without coating. Visible darkfield reflectance spectra were converted to L*a*b* color values and Kubelka-Munk (KM) spectra. Large a* value (red) positions correspond to large band areas at 500-560 nm, possibly due to hematite-like iron oxide, while large b* value (yellow) positions to large band areas at 450-500 nm, due to epidote-like mineral. Scanning electron microscopy-energy dispersive spectrometry analyses indicated that the reddish parts are Na and K-feldspars with low Fe contents (<0.5 wt%). Raman microspectroscopy could not detect hematite-like minerals. Since some hematite-like minerals were only identified by transmission electron microscope, they are considered to be submicron microcrystals disseminated in feldspar matrices. The KM spectra for prehnite-like minerals show a weak broad band around 430 nm due possibly to a ligand field band of Fe3+ without clear Fe2+-Fe3+ inter-valence charge transfer (IVCT) bands around 720 nm. Therefore, Fe in prehnite is not considered to be present as hematite-like iron oxide, but can be mainly present as Fe3+ replacing Al3+ in the crystal structure. Since determination of physicochemical states of Fe such as valence and coordination states (Fe2+ or Fe3+, oxide or in crystal lattice, etc.) and their distributions are extremely difficult, especially in complex colored materials such as rocks, the combined microspectroscopic methods are useful for their nondestructive characterization.

RADON EXHALATION FROM GRANITIC ROCKS

Naturally occurring radionuclides such as radon (222Rn), its decay products and other elements from the radioactive series of uranium (238U and 235U) and thorium (232Th) are an important source of human exposure to natural radioactivity. The worldwide evaluation of health radiobiological effects and risks from population exposure to natural radionuclides is a growing concern. About 50% of personal radiation annual dose is related to radionuclides such as radon (222Rn), thoron (220Rn), radium (226Ra), thorium (232Th) and potassium (40K), which are present in modern materials commonly used in construction of dwellings and buildings. The radioactivity of marbles and granites is of big concern since under certain conditions the radioactivity levels of these materials can be hazardous to the population and require the implementation of mitigation procedures. Present survey of the 222Rn and 220Rn activity concentration liberated in the air was performed using commercialized Brazilian granite rocks at national market as well as exported to other countries. The 222Rn and 220Rn measurements were performed using the AlphaGUARD instant monitor and RAD7 detector, respectively. This study was performed at the Applied Nuclear Physics Laboratory of the Federal University of Technology – Paraná (UTFPR). Obtained results of radon concentration activity in air exhaled studied samples of granites varied from 3±1 Bq/m3 to 2087±19 Bq/m3, which shows that some samples of granitic rocks represent rather elevated health risk the population.

Experimental evidence for mineral-controlled release of radiogenic Nd, Hf and Pb isotopes from granitic rocks during progressive chemical weathering

The role of accessory minerals in the incongruent release of Hf and Pb during continental weathering and its implications for the generation of distinct seawater isotope compositions is subject of debate. While it has been suggested that radiogenic Hf and Pb isotope signatures released during the dissolution of rocks are controlled by the relative abundances of minerals with distinct isotope compositions and differences in their resistance to dissolution there has not been a comprehensive experimental investigation of these processes to date. We carried out systematic sequential leaching experiments on fresh and partly weathered granitic rock samples as well as separated zircons from the Central Aar Granite in Switzerland. Combined with major and rare earth element concentrations our new quantitative experimental data reveal systematic preferential release of radiogenic Nd, Hf and Pb isotopes primarily controlled by dissolution characteristics of the host rock's easily dissolvable accessory and major minerals, in particular apatite and sphene, during weak chemical weathering. Moreover, Pb isotope signatures of incipient weathering conditions, contrary to expectations, indicate initial congruent release of Pb from freshly exposed mineral surfaces that becomes subsequently incongruent. During more advanced chemical weathering stages, as well as enhanced physical weathering conditions, the dissolution of major minerals (i.e. feldspars) becomes dominant for Nd and Pb isotope signatures, whereas Hf isotopes are still dominated by contributions from highly radiogenic accessories.Additional leaching experiments of zircon separates were performed to test the specific role of zircons for Hf isotope compositions of riverine runoff. It is demonstrated that zircon is more efficiently dissolved when physical weathering is enhanced. This increased Hf release originating from partial dissolution of zircons, however, is quantitatively not sufficient to explain less radiogenic Hf isotope signatures in seawater during episodes of enhanced mechanical erosion alone. Moreover, the observed addition of Hf from the more congruent dissolution of the zircon-free fractions of the parent rock due to enhanced physical weathering indicates that these minerals also play an important role in controlling Hf isotope signatures released under deglacial conditions.

The annual effective dose of granite rock samples using alpha track detector

Radon concentration and annual effective dose for granite samples collected from Abu Rusheid area, South Eastern Desert, Egypt, were measured using passive technique with CR-39. It is important to ...

Considerable radioactivity levels in the granitic rocks of the central areas of the Eastern Desert, Egypt.

The distribution of the natural radioisotopes 238U, 226Ra, 232Th, and 40K in addition to their radiological parameters in granitic rock samples from five different localities (Gebel El-Missikat, Gebel El-Gidamy, Gebel Ria El-Garra, Gebel El-Aradiya, and Gebel Kab Amira) in the central area of the Eastern Desert, Egypt, was measured using high purity germanium (HPGe) detector-based γ-spectrometry. The average activity concentrations of 238U, 226Ra, 232Th, and 40K in all five studied areas are higher than the corresponding global average values. The highest average activity concentrations of 238U and 226Ra were observed in Gebel El-Missikat, whereas the highest average value of 232Th activity concentration was found at Gebel El-Gidamy, and the highest concentration of 40K was obtained at Gebel El-Aradiya. The radiological hazard parameters radium equivalent (Raeq), external hazard index (Hex), internal hazard index (Hin), absorbed dose rate (ADR), annual effective dose rate (AEDR) outdoors, annual gonadal dose equivalent (AGDE), and excess lifetime cancer risks (ELCR) were calculated to assess the radiation hazards associated with the rock samples. The average values of these parameters are higher than the recommended reference levels. The obtained data provide a valuable future database for estimating the impact of radioactive contamination in the studied area and in the places where the rocks are used.

Modelling the diffusion-available pore space of an unaltered granitic rock matrix using a micro-DFN approach

In sparsely fractured rock, the ubiquitous heterogeneity of the matrix, which has been observed in different laboratory and in situ experiments, has been shown to have a significant influence on retardation mechanisms that are of importance for the safety of deep geological repositories for nuclear waste. Here, we propose a conceptualisation of a typical heterogeneous granitic rock matrix based on micro-Discrete Fracture Networks (micro-DFN). Different sets of fractures are used to represent grain-boundary pores as well as micro fractures that transect different mineral grains. The micro-DFN model offers a great flexibility in the way inter- and intra-granular space is represented as the different parameters that characterise each fracture set can be fine tuned to represent samples of different characteristics. Here, the parameters of the model have been calibrated against experimental observations from granitic rock samples taken at Forsmark (Sweden) and different variant cases have been used to illustrate how the model can be tied to rock samples with different attributes. Numerical through-diffusion simulations have been carried out to infer the bulk properties of the model as well as to compare the computed mass flux with the experimental data from an analogous laboratory experiment. The general good agreement between the model results and the experimental observations shows that the model presented here is a reliable tool for the understanding of retardation mechanisms occurring at the mm-scale in the matrix.

Precursor-directed combinatorial biosynthesis of cephalosporin analogue by endolithic actinobacterium Streptomyces sp. AL51 by utilizing thiophene derivative.

Natural products or their derivatives provide a reliable resource for new drugs. The multi-step chemical reaction to produce new drug is not only expensive but also release pollutants. The precursor-based combinatorial biosynthesis (PCB) is, however, a better option to produce novel natural products with potential pharmaceutical applications. The present work is an attempt to synthesize an antibacterial compound by transforming thiophene precursor using endolithic Streptomyces sp. AL51. The Streptomyces sp. AL51 was isolated from a granite rock sample collected from Mylliem, Meghalaya, India. The isolate was identified as Streptomyces sp. based on its cultural, morphological, biochemical and molecular characteristics. The bioactive compound CAx1 was extracted from the fermentation broth. The compound was characterized by bioactivity-guided fractionation and identified by infrared, UV-visible, nuclear magnetic resonance and mass spectrometry data and identified as 7-[1-(thiophene-5-yl)-1-formamido]-3-propylenyl-3-cephem-4-carboxylic acid with molecular formula C15H14N2O4S2. The purified compound showed considerable in vitro antibacterial activity against both Gram-positive and Gram-negative bacteria showing its broad spectrum property. The obtained results provide promising baseline information for the potential use of endolithic actinobacterium for semisynthetic drug discovery. This is the first report on PCB of broad range antibacterial compound by endolithic Streptomyces strain.

Excessive lifetime cancer risk and natural radioactivity measurements of granite and sedimentary rock samples

Excessive lifetime cancer risk and natural radioactivity measurements of granite and sedimentary rock samples

Proposing a new model to approximate the elasticity modulus of granite rock samples based on laboratory tests results

An accurate examination of deformability of rock samples in response to any change in stresses is deeply dependent on the reliable determination of properties of the rock as analysis inputs. Although Young’s modulus (E) can provide valuable characteristics of the rock material deformation, the direct determination of E is considered a time-consuming and complicated analysis. The present study is aimed to introduce a new hybrid intelligent model to predict the E of granitic rock samples. Hence, a series of granitic block samples were collected from the face of a water transfer tunnel excavated in Malaysia and transferred to laboratory to conduct rock index tests for E prediction. Rock index tests including point load, p-wave velocity and Schmidt hammer together with uniaxial compressive strength (UCS) tests were carried out to prepare a database comprised of 62 datasets for the analysis. Results of simple regression analysis showed that there is a need to develop models with multiple inputs. Then, a hybrid genetic algorithm (GA)-artificial neural network (ANN) model was developed considering parameters with the most impact on the GA. In order to have a fair evaluation, a predeveloped ANN model was also performed to predict E of the rock. As a result, a GA-ANN model with a coefficient of determination (R2) of 0.959 and root mean square error (RMSE) of 0.078 for testing datasets was selected and introduced as a new model for engineering practice; the results obtained were 0.766 and 0.098, respectively, for the developed ANN model. Furthermore, based on sensitivity analysis results, p-wave velocity has the most effect on E of the rock samples.

Influence of Permeability in Modeling of Reservoir Triggered Seismicity in Koyna Region, Western India

ABSTRACT The Koyna region located in the west coast of India is a classic example of reservoir triggered seismicity (RTS) that started soon after the impoundment of the Koyna reservoir in 1962. Previous studies have shown that RTS can be explained in terms of stress and pore pressure changes due to poroelastic response of the rock matrix. The permeability of rock matrix is a key parameter for pore pressure diffusion which is mainly responsible for generation of stress perturbation related to seismicity. Based on the poroelastic theory, we employ 2-D finite element models to simulate the evolution of pore pressure up to 5 years after the reservoir impoundment in 1962, using a range in permeability, 10−16-10−14 m2. Constraints on material properties of Deccan basalt and granitic rocks were taken from available studies. The results show the formation of pore pressure front and its propagation with depth and time since the reservoir impoundment as a function of permeability. While a permeability of 10−16 m2 does not produce any significant change in pore pressure, a ten-fold increase in permeability produces significant changes up to a depth of 2 km only beneath the reservoir after 5 years of impoundment. Permeability values between 10−15 m2 and 10−14 m2 are required to induce critical pore pressure changes in the range 0.1-1 MPa up to depth of 10 km, capable of triggering earthquakes in a critically stressed region. Studies on core samples of granitic basement rock down to a depth of 1522 m in the Koyna region provide evidences of fracture zones that may contribute to water channelization. Direct measurements of material properties through the ongoing deep drilling programme would help to develop more realistic models of RTS.

Structure elucidation and in silico docking studies of a novel furopyrimidine antibiotics synthesized by endolithic bacterium Actinomadura sp. AL2.

On screening of endolithic actinobacteria from a granite rock sample of Meghalaya for antibacterial compound, a novel antibacterial compound CCp1 was isolated from the fermentation broth of Actinomadura sp. AL2. On purification of the compound based on chromatographic techniques followed by characterization with FT-IR, UV-visible, 1H NMR, 13C NMR and mass spectrometry, the molecular formula of the compound was generated as C20H17N3O2, a furopyrimidine derivative. In vitro antibacterial activity of the compound was evaluated against both Gram positive and negative bacteria by agar well diffusion assay. The compound had lowest MIC (2.00µg/ml) for Bacillus subtilis and highest MIC (> 64µg/ml) for Staphylococcus epidermidis and Pseudomonas aeruginosa. The study revealed that the compound has potential antibacterial activity. The mode of action of the antibacterial compound was evaluated through in silico studies for its ability to bind DNA gyrase, 30S RNA molecules, OmpF porins and N-Acetylglucosamine-1-phosphate uridyltransferase (GlmU). The antibacterial compound demonstrated more favorable docking with DNA gyrase, 30S RNA molecules and OmpF porins than GlmU which support the antibacterial compound CCp1 can be as a promising broad spectrum antibiotic agent with "multitarget" characteristics.

Determination of uranium in Egyptian graniteic ore by gamma, alpha, and mass spectrometry

ABSTRACTThree methods were employed for the determination of uranium in granitic ore rock samples. Gamma spectrometry is a non-destructive technique while alpha spectrometry and inductively coupled plasma–mass spectrometry (ICP-MS) are destructive methods needing application of radiochemical separation before uranium measurement. In gamma spectrometry, the activity concentration of uranium is measured via its daughter (234mPa) in the decay series, while in alpha spectrometry and inductively coupled plasma mass spectrometry (ICP-MS), the activity concentration of uranium is measured directly. The activity concentrations of uranium in the samples by gamma spectrometry were between 36.7 ± 0.5 and 239 ± 2.3 Bq g−1. The activity concentrations of uranium by alpha spectrometry and ICP-MS were from 28.7 ± 1 to 145 ± 1 Bq g−1 and 34.3 ± 1.4 to 155.9 ± 1.6 Bq g−1, respectively. The ICP-MS and alpha spectrometry methods provided reliable results. The uranium concentrations obtained by gamma spectrometry were, however, systematically too high.

Evaluating the importance of different coupled thermal, hydraulic, mechanical and chemical process simulations during fluid flow experiments in fractured novaculite and fractured granite

Fluid migration in the subsurface has the potential to induce changes in fluid pressure distribution, temperature distribution, mechanical stresses and the chemistry of both the fluid and the natural geological material it is flowing through. In many situations, the change in all of these processes gives a coupled response, in that one process feeds back to another. When trying to understand fluid flow through naturally and artificially fractured systems, it is important to be able to identify the relative importance of the processes occurring and the degree of interactions between them. Modelling of such highly nonlinear coupled flow is complex. Current and predicted computational ability is not able to simulate discretely all the known and physically described processes operating. One approach to coping with this complexity is to identify the relative importance and impact of relevant processes, dependent on the application of interest. Addressing such complexity can be particularly important when the characteristics of natural and disturbed geological materials are being evaluated in the context of disposal of radioactive waste or other geo-engineering systems where an understanding of the long-term evolution is required. Based on a series of coupled (THMC—Thermal, Hydraulic, Mechanical and Chemical) experimental investigations on the flow of fluid through fractured novaculite and granite crystalline rock samples, several couplings are examined where there is both a significant kinetic chemical control as well as mechanical and temperature control on the fluid flow behaviour. These interactions can be shown both in the literature and experimentally to have a significant effect on the rate of fluid flow through fractures. A new discrete numerical approach and a new homogenous approach are used to model the experimental results of coupled flow through fractures. The results of these modelling approaches are benchmarked both against one another and against the experimental results, and then the processes included in the approaches are ranked in order of impact.

Transmissivity of aligned and displaced tensile fractures in granitic rocks during cyclic loading

The pressure dependent fracture permeability of four granitic rock samples was determined in a triaxial test cell under hydrostatic loading conditions at a temperature of 30°C. Tensile fractures were generated in cylindrical samples by Brazilian tests. Confining pressures were cycled twice between 2 and 50MPa. Permeability and strain responses were determined for two samples with aligned fracture surfaces and for two samples with a shear displacement of 1mm. Fracture apertures were also determined optically before and after testing and the fracture surfaces were scanned. Permeability of the intact granite matrix is below 1e−18m2 and sample permeabilities of fractured samples range between 1e−17m2 and 1e−12m2 depending on displacement and confining pressure. Fracture permeabilities of the aligned samples range from 1e−12m2 to 2e−10m2 and samples with displaced fracture surfaces have fracture permeabilities between 1e−11m2 and 2e−9m2. Without shear displacement, fracture permeability is reduced with time, even at low constant confining pressures of 2MPa, while fracture permeability is constant at the same conditions for the displaced samples. With increasing confining pressure, permeability reduction is significantly less for the displaced samples compared to the aligned samples. Fracture permeabilities of displaced fractures in granites are similar to fracture permeabilities in sedimentary rocks using proppants. The results indicate that self-propped displaced fractures in granites may allow sufficient fluid flow for reservoir engineering purposes such as enhanced geothermal system development, without the use of propping agents.